[Melbourne-pm] Regexps - how does the lexical scope of capture buffers work? (Was: Regexp: What's the right way to do this?)

Shlomi Fish shlomif at shlomifish.org
Wed Oct 17 04:38:26 PDT 2012


Hi Nathan,

On Wed, 17 Oct 2012 21:36:56 +1100
Nathan Bailey <nathan.bailey at monash.edu> wrote:

> I really wish I had obfuscated the contents of the regexps :-(
> 
> My question, which I thought I had clearly stated, related to the
> lexical scope of capture buffers, and why one approach to capture
> buffers worked and another didn't.
> 
> Let's try again:
>       #if (($start_time) = m#^\s*(\d+:\d+) -#) {
>       if (m#^\s*(\d+:\d+) -#) {
>          $start_time = $2;
>       #} elsif (($finish_time) = m#^\s*(\d+:\d+)#) {
>       } elsif (m#^\s*(\d+:\d+)#) {
>          $finish_time = $1;
>          $event++;
>      }
> 
> Why is $start_time undefined when we get to $finish_time in the first
> version (commented out) and not in the second?
> 
> And is there a good/better way to collect multiple values over
> multiple lines than this?
> 

Your code is hard to follow. Can you post a reproducing example for the issue
you're trying to resolve, without the need to uncomment stuff? You can also
post a working and non-working version.

Regards,

	Shlomi Fish

> thanks,
> Nathan

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